Regular high-school boy Kaji Rikuo's life is suddenly interrupted by a cute girl with cat ears named Vanilla. According to Vanilla, she was created from different mixtures of animals sort of like a chimera by her master, Ibu Kiriko, whom apparently has it out for Rikuo. Confused as to why somebody would want revenge on him, Rikuo become friends with the clueless and cute Vanilla. However, Vanilla can turn into a vicious animal able to hurt Rikuo with a simple command from Kiriko...